Silica-Based Basic Sorbent for Acid Gas Removal

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Solution Overview

Problem

Current emission control strategies for acidic gas species like HCl, SO2, and SO3 are inefficient and costly, with sodium-containing sorbents being expensive and prone to fouling, while hydrated lime reactions are less efficient, necessitating a more effective sorbent for acid gas emission control.

Innovation Solution

A sorbent composition comprising silica (SiO2) and a basic inorganic solid, such as calcium hydroxide, with a hygroscopic component that maintains a moist environment for enhanced acid gas absorption, eliminating the need for humidification and providing improved surface area and pore volume for efficient acid species capture.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If sodium-containing sorbents are used for acid gas removal, then acid gas capture efficiency is improved, but cost increases and equipment fouling occurs

Engineering Contradiction:
Improveacid gas capture efficiencyVSAvoidequipment fouling
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters by using calcium-based sorbents with specific Ca/Si ratios (1:1 to 4:1) and controlled moisture content (5-20%), optimizing the physical and chemical properties to achieve high acid gas capture efficiency without the fouling issues associated with sodium-containing sorbents

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite sorbent material combining calcium oxide or calcium hydroxide with silica, forming a composite structure that leverages the high reactivity of calcium-based compounds for acid gas capture while silica provides structural stability and prevents equipment fouling

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If hydrated lime is used for acid gas removal, then cost is reduced, but reaction efficiency decreases

Engineering Contradiction:
Improvesorbent costVSAvoidreaction efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent optimizes the moisture content parameter to 5-20% and controls the Ca/Si ratio between 1:1 and 4:1, transforming the physical state of calcium-based sorbents to enhance reaction efficiency while maintaining cost-effectiveness compared to traditional hydrated lime

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent utilizes the porous structure of the calcium oxide/calcium hydroxide-silica composite to increase surface area and active sites for acid gas reactions, thereby improving reaction efficiency while keeping the sorbent cost-effective

Inventive Principle:
Principle #31Porous materials

3Productivity

If silica-containing sorbent with controlled moisture is used, then acid gas absorption is enhanced, but sorbent formulation complexity increases

Engineering Contradiction:
Improveacid gas absorption efficiencyVSAvoidsorbent formulation complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent establishes specific parameter ranges for moisture content (5-20%) and Ca/Si ratio (1:1 to 4:1) that optimize acid gas absorption efficiency while providing clear formulation guidelines that prevent excessive complexity in sorbent preparation

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The sorbent composition achieves improved HCl capture and reduced environmental impact by maintaining a locally moist environment, offering economic, processing, and performance advantages over conventional sorbents, with enhanced efficiency compared to trona and hydrated lime.

Implementation Method 1

B is a hygroscopic solid at a preferred water to solid molar ratio of about 0.1 to about 6

Methodology Applied
Scientific EffectHygroscopic: Absorption (physical)

Implementation Method 2

basic materials are injected into the flue gas stream to contact the gas and neutralize acid gases, including hydrogen halides, SO2, SO3

Methodology Applied
Scientific EffectNeutralization reaction: Chemical Bonding

Data Source

PatentUS9475030B2Silica containing basic sorbent for acid gas removal
Publication Date: 2016.10.25 ECOLAB USA INC
  • US9475030B2 patent drawing
  • US9475030B2 patent drawing

AI summary

An acid gas sorbent composition is disclosed. The composition comprises a compound having the following formula: (SiO2)x(OH)yF.B wherein F optionally exists and said F is at least one of the following: a functionalized organosilane, a sulfur-containing organosilane, or an amine-containing organosilane; and wherein B is a hygroscopic solid at a preferred water to solid molar ration of about 0.1 to about 6, and more particularly, B is a basic inorganic solid including, but not limiting to, alkali to alkali-earth metal oxides, hydroxides, carbonates, or bicarbonates, containing at least one of the following metal cations: calcium, magnesium, strontium, barium, sodium, lithium, potassium, cesium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, dysprosium, scandium, ytterbium, yttrium, or erbrium; wherein the molar ration of y/x is equal to about 0.01 to about 0.5.